In practical communication networks, such as networks employs GSM (Global System for Mobile Communications), CDMA (Code Division Multiple Access), UMTS (Universal Mobile Telecommunications System) and LTE (Long Term Evolution) technologies, wireless communication users' demand for faster, more reliable, and better multimedia is growing. To accommodate such a growing demand, schemes capable of providing a wide bandwidth have being researched.
Taking the LTE system for example, due to the wide bandwidth requirement, carrier aggregation (CA) is being standardized in 3GPP as part of LTE Release 10, which allows for aggregating non-contiguous spectrum fragments across multiple carriers. Since some operators have access only to rather limited amount of existing spectrum to be used for LTE, it is difficult to provide high data rate LTE services. Accordingly, there is a demand for the LTE system to exploit more additional licensed spectrum.
For solving spectrum scarcity on frequency band and spectrum under-utilization on some other additional licensed band, a spectrum authorization scheme is proposed, named “Authorized Shared Access (ASA)”, which allows for a shared use of spectrum using cognitive radio technologies (geo-location databases, sensing, etc.) based on an individual authorization model of spectrum rights, and can act as a regulatory enabler to making available, in a timely manner, harmonized spectrum for mobile broadband while overcoming time, resource and political constraints.
For the ASA spectrum scheme, it is generally assumed that a Macro base station (BS) utilizes existing spectrum as a primary cell (PCell) to provide basic radio-resource control (RRC) signaling and possible low-rate/high-reliability user data; meanwhile, additional licensed carrier under ASA control is used as a secondary cell (SCell) to provide increased capacity. Considering the mobility of ASA spectrum, there is a need to maintain and enhance existing networks for service continuity, as well as load balance and handover scheme. However, there are no existing solutions for scheduling radio resources in a communication system employing the ASA scheme.
In view of the foregoing problem, there is a need to design a solution for scheduling radio resources in a communication system employing the ASA scheme, so as to improve service continuity, load balance and spectrum bandwidth of the communication system.